The Change
by LittleLongHairedOutlaw
Summary: *Prequel to 'Late Nights in Baker Street'* The bomb explodes at the pool, and shots are fired. Sherlock will likely die, unless John does the one thing that he can.
1. Bombing in Baker Street

**A/N: If I'm honest, I hadn't intended to post this here and it's already over at AO3. But some people have been wondering about some of the background to 'Late Nights in Baker Street', so here it is. (Or at least, some of it. There's lots more where this came from.)**

* * *

The first two months that John and Sherlock were together was the time of their lives - or at least, of Sherlock's life. Sherlock took cases, and John helped him at night, before they rolled into Sherlock's bed together. On one level, it seemed too amazing to ever end.

On another level, it was too amazing to never end.

* * *

The bomb in Baker Street happened to go off on a night that John was out hunting. (By hunting, he meant sneaking sips of blood off unsuspecting Londoners, but never enough to harm any one individual. He had been a doctor, after all.) However, he was still within hearing distance of the flat, having long-ago realised the damage that Sherlock could cause if left alone too long. (The wall was a fine testament to that.)

So when he heard the blast, only for a heartbeat did his thoughts drift back to Korea, and then he ran. (Though if Sherlock was dead, he knew that there was nothing that even he could do.)

Of course, Sherlock wasn't dead. There was hardly even a scratch on him aside from a cut over his eye, and the ringing left in his ears from the explosion. John kissed him, automatically licking the blood even against his better judgement. (He couldn't help himself, it tasted far too good.) After tidying the mess left in the flat, and assuring themselves that Mrs Hudson was perfectly fine (John had forgotten her in his rush to see Sherlock), they called it an early night and retired into bed.

But John soon had more worrying things on his mind than sleep. In fact, sleep soon seemed perfectly impossible.


	2. Disturbing Declarations

"If it ever looks bad for me," Sherlock murmured into the dark soon after they'd settled in for the night/morning, "if ever it looks as if I'm too badly injured to survive, then I want you to change me."

John was sure that if he'd still had a heartbeat, then it would have faltered that night. The thought of losing Sherlock was incomprehensible. The thought of giving him this life of darkness, even more so.

"Are you sure -"

"Yes." The emphasis on that single syllable was enough, but Sherlock went on anyway. "I've thought about this long and hard, and my mother offers to bite me every year on my birthday, has done since I was about twelve. But I've decided that I want you to do it, instead. I'd prefer to be a vampire and live on blood alone, than to be tied to the phases of the moon."

"If you're sure." John was reluctant, and he knew that Sherlock could hear it.

"I am. Believe me, I am. I trust you to judge whether or not I can be saved by human medicine. And if you come to the conclusion that I can't, then you have to be ready. You can't hesitate. We wouldn't have time for that." He kisses John softly. "I need you to do this for me."

Well, if Sherlock was sure . . . Better to have him a vampire than in the grave, perhaps. (Though the choice was one that no one could relish having to make.)

"I will."

And deep down, John knew he would.


	3. Explosion At The Pool

The promise comes back to John only a few nights later, by the side of the pool, Sherlock with the gun pointed at the bomb vest, Moriarty completely unconcerned, as if it is a perfectly ordinary evening and the three of them wound up at the pool by simple coincidence. (The sniper light dancing over Sherlock's body notwithstanding.) And so, the promise comes back to John, because he has to be ready to pounce.

Sherlock pulls the trigger, and through the roar in his ears as he jumps, John hears two sniper shots, simple, precise, almost lost in the world collapsing around them as they hit the water. John's only concern is for Sherlock, bullets being insufficient to take down a vampire, but there is still too much debris falling, the air too full of dust and ash, to risk resurfacing.

Images flash before his eyes, memories of a human life long gone. Korea in '51. Hot sun beating down. A landmine. Disembodied limbs in that land of death and heat. Blood-drenched sand.

John blinks, back in the present, flashback fading away. Sherlock's eyes are closed, head lolling limply, lips faintly blue, no bubbles rising although he should be trying to breathe, only a trail of blood from his chest, colouring the water so that John can taste it and it almost - but only almost, because this is Sherlock and Sherlock bloody needs him fully functioning goddammit - almost sends him into a frenzy.

He feels the supernatural, undead strength flowing into his muscles and – instead of the instinctive killing-spree - uses it to pull Sherlock out of the water, eyes still closed, face so pale as to be almost translucent, blood oozing from his leg and chest and - and oh, fuck, that's where his inferior fucking vena cava is.

John presses two fingers to Sherlock's wrist, but he can't find a pulse and he knows he isn't breathing because his lungs are too full of water, so he reaches for Sherlock's neck, seeks out the carotid, and there it is, weak, thready, but thank God it's actually there. At least he still has some chance.

He tilts Sherlock's head back, takes a breath, clamps his lips tight to Sherlock's mouth and blows it in, relieved that being a vampire he's able to pass on more oxygen than a human. But Sherlock still doesn't start breathing, doesn't do anything except lie there bleeding with a barely beating heart and hands that are so cold, hair a sopping mess over his pale forehead. And fuck it all, but he's not allowed to die today.

So John uses one hand to pinch Sherlock's nose and with his other hand kneads his breastbone as he breathes for him - three breaths, four breaths, five, and he can taste the chlorinated water and with the hand on Sherlock's chest feels the erratic heartbeat, feels the gasp for breath, the cough before it comes, and carefully rolls him onto his side as he chokes out water, no blood, thankfully. Sherlock sighs when he catches his breath, rattly and hoarse as it is, eyes half-open and glazed as they search John's face before sliding closed again, a low broken moan escaping his lips, blood still oozing from the bullet holes (because neither bullet hit an artery, but it is the IVC so most of the blood is inside but not inside, damaging those precious, delicate organs with deprivation and too much pressure.)

And for the second time that night, John's promise comes back like a nauseating punch to the gut.


	4. Bloody Estimations

Eight minutes. Eight minutes is the average arrival time of a London ambulance, and John estimates that there might be two and a half minutes gone since Sherlock shot the bomb. He also estimates that with the likelihood of an ambulance being on the way once the explosion gets phoned in, then at the very most he has ten minutes to make up his mind.

But Sherlock doesn't have ten minutes, not at the rate that he's bleeding, even with John pinching his IVC to stop the blood flow. So there's only one thing left to do, really.

He withdraws his fingers from the bullet hole, and tears a strip of cloth off Sherlock's shirt, carefully packing it into the wound like he's done hundreds of times before back in Korea, and repeating the process with the hole through his leg. Sherlock never stirs, never even moans, and John's half hoped that the pain would bring him out of it.

Evidently not. Onto step two.

John rolls back his sleeve, and dips his tongue into Sherlock's blood. His fangs extend just as they're meant to, and he sinks them into his arm, tearing a gash when he pulls them out again. The dark blood half-oozes, half-slides, not at all like the way that it would gush if he were human. Carefully he props up Sherlock's limp head, and puts the blood to his lips. It dribbles down his chin, and even unconscious Sherlock gags on the taste, John silently willing him to drink it, which he does after a moment, taking deep gulps as if it will give him life instead of taking it. (And John really hates himself for this, but Sherlock's told him it's what he wants, and John knows that if he lasted as far as the hospital (unlikely) then he wouldn't last too much longer, so it has to be this way. But it doesn't have to come easy for the vampire. Though, he now knows, he'd do it anyway. Because Sherlock always has to exist, in some form or another. He can't just be . . . gone.)

When John senses Sherlock's drank enough blood (and so much of this is instinct), he withdraws his arm, binding it tightly with more of Sherlock's shirt. They only have a handful of minutes before the ambulance and police are bound to arrive, so John kisses his dying lover softly on the forehead, before scooping him into his arms and running.


	5. Further and Further Out of Reach

Nobody sees John as he runs through the streets of London back to Baker Street, Sherlock cradled to his chest, head lolling limply against John's shoulder, curls brushing his ear, breath against his neck. The city passes in a blur, cars, people, ambulances, police and firemen all heading towards the pool. John ignores them all, simply concentrating on that huff of air against his throat, knowing that it won't be there for much longer.

The door swings open as they get there, Mrs Hudson standing back against the wall.

"I had a feeling," she says as John passes her, heading for the stairs. "I'll be up in just a minute."

John hardly hears her as he thunders up to 221B, Sherlock's breath growing weaker and harsher, body failing. He carries Sherlock into the bedroom and lays him out on top of the sheets, ripping open his trousers and shirt (well, what remains of it) to be able to work better. Checking that the bullet wounds are still plugged – though there is blood seeping through the cloth, staining the delicate, pale skin crimson – he goes into the sitting room and rummages for the candles from some experiment that Sherlock conducted not too long ago. He carries them back into the bedroom and arranges them on all of the available surfaces, lighting each with a lighter that he plucked out of Sherlock's coat a few days ago. (And where is the coat now? Either lost in the explosion or Sherlock hadn't worn it, which would be surprising. But there are more important things to worry about.)

Mrs Hudson appears in the doorway with a box of stuff and goes to Sherlock, carefully easing the bloodied cloth out of the leg wound while John starts work on the chest hole. As quickly as they can, they stitch the two wounds, paying no mind to infection or anything of the sort. (Irrelevant now, a voice says in John's head, more important to keep blood in his veins by whatever means necessary. He's dying tonight anyway.)

As Mrs Hudson tenderly cleans away the spilled blood marring Sherlock's skin, John reaches for the knife that she brought up with her and slits the tip of his finger, painting a cross on Sherlock's forehead and over his heart with the oozing, sluggish blood. Then he lifts Sherlock's hand – fingers of one hand over the pulse point, though there's no pulse there because his blood pressure is far too low, heart struggling to do its work – and cuts into the palm, pressing his still-bleeding finger to the gash. (So much blood involved in this ritual, and John is glad he doesn't remember his own Change. Too far out of his mind at the time with pain and blood loss.)

Through the blood, John feels Sherlock slipping further and further away, knows it's only a matter of time before he's clinically dead, knows there are still five days of waiting before they know for sure whether or not this will work, knows Sherlock could be really dying in front of him, not just dying before coming back. (This changing isn't fool proof, has its failures. Too little human blood left in a body. Simple incompatibility. So many other reasons that any of them could apply here and now, in this night and the ones to come.)

And it's this knowledge which feels like a leaden weight in John's chest.

All they can do still may not be enough, because this doesn't always work and John has seen others die after everything has been done to change them.

Surely Sherlock won't be one of them.

But why should he be exempt from the laws governing vampire Changes? John doesn't have the power to decree anything like that. The only power he has right now is to give Sherlock as best a chance as possible.

But that just isn't good enough, in anyone's opinion.

After the blood exchange, John kisses each of Sherlock's fingers on the hand that he's holding and lays it down beside his limp body, hoping there's some part of that magnificent brain which is able to register that he's here with him, that he's not dying alone.

His own fingers move to Sherlock's throat, seeking out the carotid again, because soon he's going to stop breathing and it's only a matter of time until his heart quits then, and John wants to know the moment that the life leaves his body. Even if it's only temporary.

And there's so much that John wants to say, just in case he never gets the chance to again, and he's never told Sherlock just how much he loves him, but his throat is too clogged with the tears that he hasn't been able to cry for nearly sixty years and he can't make his voice work and it's all too much. Too much emotion, too much worry, piling up together. (Too much of Sherlock's blood soaked into his clothes along with the pool water, and Sherlock's hair is still wet from it, slowly drying in stiff, dark ringlets that he can never cut again because otherwise it won't grow out, and Sherlock adores those curls. And how has everything come to this? How is his humanity ending like this? How the hell does anyone deserve this?)

All they can do is all that they have done. Now all that's for it is hoping, and praying, and isn't praying such an ironic thing for a vampire to do, John thinks. It's not as if either of them is going to get into heaven anyway. Not anymore.


	6. Final Beat

"Oh, God." It comes in the form of a sigh, breathed from the doorway, and John is almost surprised to realise that it's Mycroft of all people sounding so worried, face pale, eyes hollow, façade dropped in the face of so much heartache. He crosses the room to Sherlock's other side, looking so undone as he strokes back his little brother's hair that John can hardly believe that this is the indomitable Mycroft Holmes.

Of course, no reaction comes from Sherlock. Not so much as a whimper.

John opens his mouth, but doesn't know what to say so he closes it again, instead counting the pause between Sherlock's faint breaths. Twelve seconds, give or take. Far too long, but about all that can be expected right now.

"Mummy will be here in about five minutes," Mycroft says quietly. "Do you think he has that long?"

John nods. "Just about," he murmurs. "My blood has slowed it down, but I was worried that I wouldn't have enough time to get it into his system at the pool, and I needed to stop the bleeding first."

"I know." Mycroft leans in, and whispers quietly into Sherlock's ear, pressing a soft kiss to his temple. John manages not to listen, noticing instead that Sherlock's breaths are hardly even earning that title, bordering on the horrible, agonal stage of lungs which have failed. He knows it has to be this way, but dear God it's difficult to watch.

John's ears catch the sound of footsteps racing up the stairs, and Violet Holmes stops in the doorway like Mycroft before, her hair wild and face white. She swallows when her eyes fall on Sherlock's frail form, and a single tear trickles down her face as she crosses the room, sinking to her knees beside the bed and bowing her head, pressing his fragile hand to her lips.

"Oh, Sherlock," she whispers. "Oh, my baby. You just fight as hard as you can, okay? Please come back, sweetheart. Don't stay gone." Of course, she knows the odds as well as any of them in that room, gathered around that bed, waiting though they're aching inside. Lover, brother, son, surrogate son, dying before their eyes and there's nothing that any of them can do, except hope that the grief and distance is only temporary, only lasts the required five days and not forever.

John swallows, wishing that he could cry, could release this twisting mess inside of him in an accepted expression of grief. But he can't, so he simply presses his lips gently to Sherlock's, knowing it will be the last time that they feel relatively warm beneath his, so soft and delicate. Both tender and cutting all at once. Mrs Hudson doesn't say anything, just stands beside John with tears in her eyes, rubbing her thumb gently over Sherlock's forehead and wishing that her magic was enough to change this. (The magic has never existed to heal the dead, and that's what Sherlock pretty much is now, even if his heart is still, somehow holding on.) In truth, there is nothing for her to say and they all know that.

Sherlock takes his last breath about a minute later, drawing it in through those pale, parted lips. It's a shallow affair that he exhales with a sigh, and John keeps his fingers pressed to his carotid, counting each erratic heart beat until his heart stops a few minutes later. Finally fails into cardiac arrest, and it is all that John can do not to commence CPR and demand him to come back. But there is no point in something so human. Not in this bedroom of unbroken silence, filled with death and irrevocable changes.


	7. Those Left Behind

With the black-out curtains drawn, John is able to sit with Sherlock – he refuses to think of it as being Sherlock's body because this has to work, dammit, he can't be really dead - even during the day. He sits there, holding his dead and changing lover's cold hand and not saying anything, simply existing, unable to think, unable to tear himself away, watching for the insidious trail of blood from finely crafted lips that'll mean it's all been a failure.

Violet sits on the other side of her son, stroking his curls absentmindedly, too well able to think. She remembers Siger's death to save Sherlock, and knows he would be proud of the man their son has become. She also finds that she's incredibly grateful for Sherlock having met John, though she'd had her doubts about his consorting with a vampire at first (any mother would). With bullet wounds like that, a werewolf bite wouldn't have been enough to save him, and she'd be planning his funeral now for certain. (She prefers not to think that she still might be. Even if it means becoming a vampire, he has to outlive her. It's only right.)

Over that first night, Mycroft drinks half a bottle of good scotch, needing to brace himself against the onslaught of emotion building inside of him. His little brother is lying dead in the next room, the little brother that he swore to protect on the day that his father brought him home, and yet all the help that he could give wasn't enough because there had to be a madman with snipers and a bomb. He's too choked with grief to say anything, an aching in his chest that hasn't been there for ten years. (And if Mycroft can't let the pain out here, then where can he?)

And Mrs Hudson - for the simple reason that she's Mrs Hudson - takes it upon herself to look after everyone else, laying aside her own grief and fear, making sure that Mycroft and Violet eat, and John takes blood, and that they all get some sleep, even if only in shifts. Someone has to look after them, after all. It may as well be her as anybody else. (It's not doing Sherlock any good, them wearing themselves out, she reminds herself, soldiering on though that boy has been like a son to her.)

Mostly, they all just feel helpless. Unable to do anything now except wait, and see.


	8. Outside Help

Greg comes by the day after the explosion at the pool, hoping that Sherlock will be able to help with the case because they have no idea who the bomber is, though he has some suspicions of his own. (Of course, he doesn't know what's happened, not yet. Doesn't know Sherlock and John were there in the first place, so how could he expect what he's going to find in Baker Street?) And it is Mrs Hudson who tells him, explaining the story as best as she can from what John has told her. (Which isn't much because John has withdrawn into himself, better able to deal with his emotions that way, when all he is aware of around him is Sherlock lying there so pale and still and _not breathing_.)

The werewolf bite on Greg's arm burns at the sight of Sherlock laid out like that, the memory of those days of pain etched into his own mind. And although there is nothing that he can do for Sherlock, no way in which he can help, he feels compelled to try to help everyone else, to at least do something to make this interminable waiting easier. So he leaves, and goes to see Molly in the morgue, telling her what has happened and getting more blood for John, and Sherlock when he wakes (if he wakes, but Greg refuses to think like that).

What he doesn't realise is that Molly already knows, one of the ghosts having heard it from another ghost and told her. It is only when she sees Greg that she feels like breaking down, feels like giving in to the tears that have been building behind her eyes since she heard. (She hasn't wanted to believe, hasn't wanted it to have come this, has hoped it's just a rumour in the ghost community, but now she's faced with tangible proof because this is Greg of all people looking so shattered and exhausted.) Mostly, though, she's angry at herself, angry at having been taken in by Moriarty against the ghosts' advice. (They had never trusted him, and rightly so.) But she pulls herself together, and gathers some blood for Greg to take back to Baker Street.

It's all that's left for her to do now, anyway.


	9. Five Days

The five days pass, as they were always going to. John and Violet only leave Sherlock's side in order to sleep, although they were doing nothing constructive there, feeling irresistibly drawn back to his pale, stiff – then not so stiff once rigor mortis has passed – corpse, regardless. Mycroft manages his office from the living room of 221b, unable to bring himself to leave for any length of time (and at least Andrea understands, taking over most of it for him), and Mrs Hudson minds all of them, even Greg and Molly when they drop in after work to see how things are going on.

On the fifth night, they all gather in the bedroom, waiting. Molly has brought more blood, insisting that it will work out as it should. (John puts that down to her relentless optimism, though even he has to admit that it's looking good. But he won't allow himself to get his hopes up.)

The first sign that it's gone well, is when Sherlock's finger twitches. It's so minute a movement that John only notices because he's holding that hand, and even then he thinks he imagines it. It happens again, stronger, and this time he knows that he didn't imagine it, didn't conjure it up out of his desire for Sherlock's return. A groan escapes Sherlock's parted lips, and a furrow appears between his eyes. Now everyone knows, and even Mycroft grins, though there is still a clouded look behind his eyes. John squeezes Sherlock's hand, leaning in to murmur in his ear, assuring him that all will be fine, urging him to open his eyes. Remembering his own nausea and thirst at waking up undead for the first time, he gestures for Molly to come forward with the first bag of blood, tearing it open with his teeth and propping up Sherlock's head to feed him. With his eyes still closed, Sherlock drinks hesitantly at first, then greedily. Molly passes forward another bag, no one daring to speak, hardly even breathing.

When Sherlock finishes the third bag, he shakes his head slightly and sighs. "John." His voice is hoarse, rusty, unused for five long days. (Long doesn't begin to cover how they felt, as far as John is concerned.)

"Yeah, I'm here," he answers quietly, remembering the painful hyper-awareness of all of his senses when he first woke.

Sherlock's lip twitches into a slight smile and he blinks rapidly when his eyes open, taking in all of those who have gathered for this. (His family, really, all of them, and though he may try to deny it to everybody including himself, he knows that too.) "So glad to see everyone could make it."

"Don't you ever do that to us again," Greg growls, lip curling slightly though he is smiling, too. "Don't know what we'd do without you."

"Good to see you too, Lestrade."

Violet smiles tearily, her eyes glistening, and kisses Sherlock – who flinches and tries to evade her – on the forehead. "How do you feel?" The concern is evident under her voice.

"Substantially better than at the pool."

"Silly boy," Mrs Hudson murmurs, and Sherlock smiles at her, oddly touched at everyone waiting for him like this. (Though sentiment doesn't sit with him any better as a vampire than as a human. Some things never change.) Mycroft simply nods at him, pretending that his eyes aren't shining though Sherlock knows they are and nods back, before Molly kisses him on the cheek.

"I always knew you'd be fine," she says. "And I'm glad."

"Thank you, Molly."

And so begins the undead life of Sherlock Holmes.


	10. Early Morning Murmurs

"Thank you," Sherlock murmurs into the darkness after everyone has left with their promises to check in again on the next night. That's it now for him, living his life predominantly at night, needing the black-out curtains pulled to move around during the day, never seeing the sun again except on television. It makes him a little sadder than he thought that it would, but he'll adjust.

John sighs, carding fingers through Sherlock's hair, relieved to be back to this familiarity even if so many things are different now. "You don't have to." He's quiet for a moment before he continues on. "You know, you weren't breathing when I pulled you out of the water, and as I tried to get you to start again, I realised that I'd change you anyway, whether you'd asked me to or not. And I know it sounds selfish but, I couldn't bear to lose you, Sherlock, not so soon, not like that. Not ever, maybe. The thought of forever without your smirks and your sarcasm and your black moods, it's ridiculous but I couldn't bear it. I know that, now."

Sherlock opens his eyes and reaches up to pull John down. "I remember seeing you, and everything hurt so much and I wasn't sure if you were real or not, but I thought, well, if I'm dying, at least you'll be the last thing that I see, my last memory whether real or not. But I didn't want to leave you behind, didn't want to put either of us into that position." He swallows, feeling like crying but not being able to anymore. "I was just glad that you were there, with me."

John presses his lips softly to Sherlock's not knowing what to say, not wanting to think about those horrible moments when he was so sure that he was going to lose this wonderful man without getting to at least try to save him first. And that is how they pass this first day of undeath, gentle kisses and murmured words, each holding on so tightly out of fear and hope and relief.


End file.
